It remains for us to consider what is essentially Darwinian in Darwinism,
namely, the theory of natural selection as the determining factor in
evolution. For, given the reality of evolution and descent, and that
transformations from one form to another, from lower to higher, have
really taken place, what was the guiding and impelling factor in
evolution, what forced it forwards and upwards? It is here that the real
problem of Darwinism begins. Only from this point onwards does the
doctrine of evolution, which is not in itself necessarily committed to any
theory of the factors, become definitely Darwinian or anti-Darwinian. And
it is this problem that is mainly concerned in the discussions taking
place to-day as to whether Darwin was right, or whether Darwinism as a
hypothesis has not broken down.
The most characteristic feature of Darwin’s theory was “natural
teleology,” that is, the explanation of what is apparently full of purpose
and plan in the world, purely as the necessary consequence of very simple
conditions, without purpose or any striving after an aim. He sought to
show that evolution and ascent can be realised through purely “natural”
causes, that this world of life, man included, must have come about, but
not because it was intended so to do. In this sense, indeed, his doctrine
is an attempt to do away with teleology. But in another sense it is so
even more emphatically. The world, and especially the world of life, is
undoubtedly full of what is _de facto_ purposive. The living organism, as
a whole and in every one of its parts, is marvellously adapted to the end
of performing its functions, maintaining its own life and reproducing.
Every single living being is a miracle of inexhaustible adaptations to an
end. Whence came these? They, too, are products, unsought for, unintended,
and yet necessary, and coming about “of themselves,” that is without
teleological or any supernatural guiding principles. To eliminate purpose
and the purposive creating and guiding activity of transcendental
principles from interpretations of nature, and to introduce purely
naturalistic principles—“principles of chance,” if we understand chance in
this connection not as opposed to necessity, but to plan and purpose—this
is the aim of the Darwinian theory. And it only becomes definitely
anti-theological because it is anti-teleological.
The conclusions which Darwin arrived at as to the factors in the
transformation of species, and in the production of “adaptations,” have
been in part supported by the specialists he influenced, in part
strengthened, but in part modified and even reversed, so that a great
crisis has come about in regard to Darwinism in the strict sense—a crisis
which threatens to be fatal to it. We must here attempt to take a general
survey of the state of the question and to define our own position.
Darwin’s interpretation is well known. It is the theory of the natural
selection of the best adapted through the struggle for existence, which is
of itself a natural selection, and results in the sifting out of
particular forms and of higher forms. Darwin’s thinking follows the course
that all anti-teleological thought has followed since the earliest times.
In bringing forth the forms of life, nature offers, without choice or aim
or intention, a wealth of possibilities. The forms which happen to be best
adapted to the surrounding conditions of life maintain themselves, and
reproduce; the others perish, and are eliminated (survival of the
fittest). Thus arises adaptation at first in the rough, but gradually in
more and more minute detail. This adaptation, brought about by chance,
gives _the impression_ of intelligent creative purpose.
In Darwin this fundamental mode of naturalistic interpretation took, under
the influence of the social-economic theories of Malthus, the special form
of natural selection by means of the struggle for existence, in
association with the assumption of unlimited and fluctuating variability
in the forms of life. All living beings have a tendency to increase in
number without limit. But the means of subsistence and other conditions of
existence do not increase at the same rate; they are relatively constant.
Thus competition must come about. Any organism that is, by fortuitous
variation, more favourably equipped than its fellows maintains itself and
reproduces itself; the less favoured perish. For all things living are
exposed to enemies, to untoward circumstances, and the like. Every
individual favoured above its rivals persists, and can transmit to its
descendants its own more favourable, more differentiated, more highly
equipped character. Thus evolution is begun, and is forced on into the
ever more diverse and ever “higher.”
To Darwin this struggle for existence and this selection according to
utility seemed, at any rate, the chief factor in progress. He did, indeed,
make some concessions to the Lamarckian principle that new characters may
be acquired by increased use, and to other “secondary” principles. But
these are of small importance as compared with his main factor.
Differences of Opinion As To the Factors In Evolution.
The theory of natural selection in the struggle for existence rapidly
gained wide acceptance, but from the first it was called in question from
many sides. Bronn, who translated Darwin’s works into German, was and
remained loyal to the idea of a “developmental law”—that there is within
the organism an innate tendency towards self-differentiation and progress,
thus a purely teleological principle.(34) Similarly, von Baer emphasised
the idea of an endeavour to realise an aim; von Kölliker, that of
“heterogenesis”; Nägeli, that of an impulse towards perfection—all three
thus recognising the theory of evolution, but dissenting from the view
that the struggle for existence is the impelling factor and actual guide
in the process. Very soon, in another direction, antagonism became
pronounced between the strictly Darwinian elements of the theory (the
struggle for existence and its corollaries) and the accessory Lamarckian
elements. Through these and other controversies the present state of the
question has emerged.
The main antithesis at present is the following. On the one side, the
“all-sufficiency of natural selection” is maintained, that is, progressive
evolution is regarded as coming about without direct self-exertion on the
part of the organisms themselves, simply through the fact that fortuitous
variations are continually presenting themselves, and are being selected
and established according to their utility in the struggle for existence.
On the other side—with Lamarck—the progress is regarded as due to effort
and function on the part of the organism itself. (Increased use of an
organ strengthens it; a changed use transforms it; disuse causes it to
degenerate. Thus new characters appear, old ones pass away, and in the
course of thousands of years the manifold diversity of the forms of life
has been brought about.)
Further, by those of the one side variation is regarded as occurring by
the smallest steps that could have selective value in the struggle for
existence. To the others variation seems to have taken place by leaps and
bounds, with relatively sudden transformations of the functional and
structural equilibrium on a large scale. In regard to these the _rôle_ of
the struggle for existence must be merely subsidiary. This saltatory kind
of evolution-process is called “halmatogenesis,” or, more neatly,
“kaleidoscopic variation,” because, as the pictures in a kaleidoscope
change not gradually but by a sudden leap to an essentially new pattern,
so also do the forms of life. Associated with this is the following
contrast. One side believes in free and independent variation of any
organ, any part, any function, physical or mental, any instinct, and so
on, apart from change or persistence in the rest of the organism; the
other side believes in the close connectedness of every part with the
whole, in the strict “correlation” of all parts, in variation in one part
being always simultaneously associated with variation in many other parts,
all being comprised in the “whole,” which is above and before all the
parts and determines them. And further, to one school variation seems
without plan in all directions, simply plus or minus on either side of a
mean; to the other, variation seems predetermined and in a definite
direction—an “orthogenesis,” in fact, which is inherent in the organism,
and which is indifferent to utility or disadvantage, or natural selection,
or anything else, but simply follows its prescribed path in obedience to
innate law. The representatives of this last position differ again among
themselves. Some regard it as true in detail, in regard, for instance, to
the markings of a butterfly’s wing, the striping of a caterpillar, the
development of spots on a lizard; while others regard it as governing the
general process of evolution as a whole. Finally, there is the most
important contrast of all. On the one side, subordination, passivity,
complete dependence on the selective or directive factors in evolution,
which alone have any power; on the other, activity, spontaneous power of
adaptation and transformation, the relative freedom of all things living,
and—the deepest answer to the question of the controlling force in
evolution—_the secret of life_. This last contrast goes deeper even than
the one we have already noted, that between the Darwinian and the
Lamarckian principle of explanation; and it leads ultimately from the
special Darwinian problem to quite a new one, to be solved by itself—the
problem of the nature and secret of living matter.
Weismannism.
In regard to almost all the points to which we have referred, the most
consistent and decided champion of Darwinism in its essential principles
is the zoologist of Freiburg, August Weismann.(35) In long chapters on the
protective coloration of animals, on the phenomena of mimicry—that
resemblance to foreign objects (leaves, pieces of wood, bark, and
well-protected animals) by which the mimics secure their own safety from
enemies—on the protective devices in plants, the selective value of “the
useful” is demonstrated. In regard to the marvellous phenomena of
“carnivorous” plants, the still more marvellous instincts of animals,
which cannot be interpreted on Lamarckian lines as “inherited habit,” but
only as due to the cumulative influence of selection on inborn tendencies,
as well as in regard to “symbiosis,” “the origin of flowers,” and so on,
he attempts to show that the heterodox attempts at explanation are
insufficient, and that selection alone really explains. At the same time
the Darwinian principle is carried still further. It is not only among the
individuals, the “persons,” that the selective struggle for existence goes
on. Personal selection depends upon a “germinal selection” within the
germ-plasm, influencing it, and being influenced by it—for instance,
restrained.
In order to explain the mystery of heredity, Weismann long ago elaborated,
in his germ-plasm theory, the doctrine that the developing individual is
materially preformed, or rather predetermined in the “idants” and “ids” of
the germ-cell. Thus every one of its physical characters (and, through
these, its psychical characters), down to hairs, skin spots, and
birth-marks, is represented in the “id” by “determinants” which control
the “determinates” in development. In the course of their growth and
development these determinants are subject to diverse influences due to
the position they happen to occupy, to their quality, to changes in the
nutritive conditions, and so on. Through these influences variations in
the determinants may be brought about. And thus there comes about a
“struggle” and a process of selection among the determinants, the result
of which is expressed in changes in the determinates, in the direction of
greater or less development. On this basis Weismann attempts to reach
explanations of the phenomena of variation, of many apparently Lamarckian
phenomena, and of recognised cases of “orthogenesis,” and seeks to
complete and deepen Roux’s theory of the “struggle of parts,” which was
just another attempt to carry Darwinism within the organism.
What distinguishes Weismann, and makes him especially useful for our
present purpose of coming to an understanding in regard to the theory of
selection is, that his views are unified, definite and consistent. In his
case we have not to clear up the ground and to follow things out to their
conclusions, nor to purge his theories from irrelevant, vitalistic, or
pantheistic accessory theories, as we have, for instance, in the case of
Haeckel. His book, too, is kept strictly within its own limits, and does
not attempt to formulate a theory of the universe in general, or even a
new religion on the basis of biological theories. Let us therefore inquire
what has to be said in regard to this clearest and best statement of the
theory of selection when we consider it from the point of view of the
religious conception of the world.
Whatever else may be said as to the all-sufficiency of natural selection
there can be no doubt that it presupposes two absolute mysteries which
defy naturalistic explanation and every other, and which are so important
that in comparison with them the problem of the struggle for efficacy and
its meaning fades into insignificance. These are the functions and
capacities of living organisms in general, and in particular those of
variation and inheritance, of development and self-differentiation. What
is, and whence comes this mysterious power of the organism to build itself
up from the smallest beginnings, from the germ? And the equally mysterious
power of faithfully repeating the type of its ancestors? And, again, of
varying and becoming different from its ancestors? Even the “mechanical”
theory of selection is forced to presuppose the secret of life. Weismann
indeed attempts to solve this riddle through his germ-plasm theory, the
predisposition of the future organism in the “ids,” determinants, and
biophors, and through the variation of the determinants in germinal
selection, amphimixis and so on. But this is after all only shifting the
problem to another place, and translating the mystery into algebraical
terms, so to speak, into symbols with which one can calculate and work for
a little, which formulate a definite series of observations, an orderly
sequence of phenomena, which are, however, after all, “unknown quantities”
that explain nothing.
In order to explain the developing organism Weismann assumes that each of
its organs or parts, or “independent regions,” is represented in the
germ-plasm by a determinant, upon the fate of which the development of the
future determinate depends. It is thought of as a very minute corpuscle of
living matter. Thus there are determinants of hairs and scales, pieces of
skin, pits, marks, &c. But every determined organ, or part, or
“independent region,” is itself in its turn an “organism,” is indeed a
system of an infinite number of interrelated component parts, and each of
these again is another, down to the individual cells. And each cell is an
“organism” in itself, and so on into infinity. Is all this represented in
the determinants? And how?
Further, the individual determinate, for instance of a piece of skin, is
not something isolated, but passes over without definite boundary into
others. Therefore the determinants also cannot be isolated, but must be
systems within systems, dependent upon and merging into one another. How,
at the building up of the organism, do the determinants find their
direction and their localisation? And, especially, how do they set to work
to build up their organ? Here the whole riddle of the theory of
epigenesis, which Weismann wished to do away with as a mystery, is
repeated a thousand times and made more difficult. In order to explain
puzzling processes on a large scale, others have been constructed, which
on close investigation prove to be just the same mysterious and
unexplained processes, only made infinitely smaller.
Moreover, even if the whole of “Weismannism,” including germinal
selection, could be accepted, and if it were as sufficient as it is
insufficient, what we advanced at the end of Chapter III. as a standpoint
of general validity in relation to teleology and theology would still hold
good. Even an entirely naïve, anthropomorphic, “supernatural” theology is
ready to see, in the natural course of things, in the “_causæ
secundariæ,_” the realisation of Divine purpose, teleology, and does not
fail to recognise that the Divine purpose may fulfil itself not only in an
extraordinary manner, through “miracles” and “unconditioned” events, but
also in ordinary ways, “through means” and the universal causal nexus.
Thus it is quite consistent even with a theology of this kind to regard
the whole system of causes and effects, which, according to the
Darwin-Weismann doctrine, have gradually brought forth the whole diversity
of the world of life, with man at its head, in a purely causal way without
teleological intervention, as an immense system of means marvellous in its
intricacy, in the inevitable necessity of its inter-relations, and in the
exactness of its work, the ultimate result of which _must_ have come
about, but perhaps at the same time was _intended_ to come about. Whether
I regard this ultimate result as the mere consequence of blind happenings,
or as an intended purpose, does not depend, as we have seen, upon the
knowledge gained by natural science, but depends above all on whether this
ultimate result seems to me of sufficient _value_ to be thought of as the
purpose of a world-governing intelligence, and thus depends upon my
personal attitude to human nature, reason, mind, and the spiritual,
religious, and moral life. If I venture to attribute worth, and absolute
worth, to these things, nothing, not even the fact of the “struggle for
existence” in its thousand forms, in its gradually transforming effects,
in the almost endless nexus of its causes and results, germinal selection
included, can take away my right (and eventually my duty) to regard the
ultimate result _as an end_, and the nexus of causes as a system of means.
To enable me to do this, it is only requisite that internal necessity
should govern the system, and that the result should not be a chance one,
so that it might even have been suppressed, have failed, or have turned
out quite differently. Necessity and predetermination are characteristic
of the relation between means and purpose. But this requisite is precisely
that which natural science does afford us,—namely, the proof that all
phenomena are strictly governed by law, and are absolutely predetermined
by their antecedents. At this point the religious and the scientific
consideration coincide exactly. The hairs of our head, and the hairs in
the fur of a polar bear, which is varying towards white, and is therefore
selected in the struggle for existence,(36) even the fluctuating
variations of a determinant in the germ, are “numbered” according to both
conceptions. Every variation that cropped up, every factor that “selected”
the fit, and eliminated the unfit, was strictly predestined, and must of
necessity have appeared as, and when, and where it did appear.(37)
The whole nexus of conditions and results, the inclined plane of evolution
and the power of Being to move up it, has its sufficient reason in the
nature and original state of the cosmos, in the constitution of its
“matter,” its “energy,” its laws, its sequences and the grouping of its
phenomena. Only from beginnings so constituted could our present world
have come to be as it is, and that necessarily. Only because the primary
possibility and fitness for life—vegetable, animal and human—was in it
from the beginning, could all these have come to be. This primary
possibility did not “come into being,” it was _à priori_ immanent in it.
Whence came this? There is no logical, comprehensible, or any other
necessity why there should be a world at all, or why it should be such
that life and evolution must become part of it. Where then lies the reason
why it is, rather than is not, and why it is as it is?
To this must be added what Weismann himself readily admits and expressly
emphasises. The whole theory treats, and must treat plant, animal, and man
as only ingenious machines, mere systems of physical processes. This is
the ideal aimed at—to interpret all the phenomena of life, growth, and
reproduction thus. Even instincts and mental endowments are so
interpreted, since there must be corresponding morphological variations of
the fine structure of the nervous organ, and instinctive actions are then
“explained” as the functions of these. But how “mechanical happening”
comes to have this marvellous inwardness, which we call sensation,
feeling, perception, thought and will, which is neither mechanical nor
derivable from anything mechanical; and, further, how physical and
psychical can condition one another without doing violence to the law of
the conservation of the sum of energy, is an absolute riddle. But this
whole psychical world exists, with graduated stages perhaps as close to
each other as in the physical world, but even less capable than these of
being explained as having arisen out of their antecedent lower stages. And
this psychical world, which is, indeed, related to and dependent upon the
corporeal life, as also conversely, has its own quite peculiar laws:
thought does not follow natural laws, but those of logic, which is
entirely indifferent to exciting stimuli, for instance of the brain, which
conform to natural laws. But this world, its riddles and mysteries, its
great content and its history, beyond the reach of mechanical theories, is
so absolutely the main thing (especially in regard to the question of the
possibility of religion), that the question of bodily structure and
evolution becomes beside it a mere accessory problem, and even the last is
only a relatively unimportant roundabout way of coming at the gist of the
business. How completely the evolution of the higher mental faculties
transcends such narrow and meagre formulæ as the struggle for existence
and the like, Weismann himself indicates in connection with man’s musical
sense, and its relation to the “musical” instinct in animals. The same and
much more might be alleged in regard to the whole world of mind, of the
æsthetic, ethical and religious, of the kingdom of thought, of science,
and of poetry.
Natural Selection.
We have for the moment provisionally admitted the theory of natural
selection, in order to see whether it could be included in a religious
interpretation of things. But in reality such an admission is not to be
thought of, in face of what is at present so apparent—the breaking down of
this hypothesis, which has been upheld with so much persistence. We shall
have to occupy ourselves with this later on. In the meantime a few more
remarks must be added to what has been already said.
It might be said, paradoxically, that the worst fate that could befall
this hypothesis would be to be proved, for then it would be most certainly
refuted. What we mean is this: If it is really “utility” that rules the
world and things, there can be no certainty and objectivity of knowledge,
no guarantee of truth. The “struggle for existence” is not concerned with
selecting beings who see the world as it is. It selects only the
interpretation and conception of the environment that is most serviceable
for the existence and maintenance of the species. But there is nothing to
guarantee that the “true” knowledge will also be the most useful. It might
quite well be that an entirely subjective and in itself wholly false
interpretation would be the most serviceable. And if, by some
extraordinary chance, the selected interpretation should be also the true
one, there would be no means of establishing the fact. And what is true of
this interpretation is true also of all theories that are derived from it,
for example of the theory of selection itself.
Furthermore, a great part, perhaps the greatest part of the confidence
placed in the theory of selection is due to an involuntary, but entirely
fallacious habit of crediting it with the probabilities in favour of the
doctrine of descent. The main arguments in favour of evolution and descent
are very often, though unwittingly, adduced in support of Darwinism in
particular. This is a great mistake. Take, for instance, the evidence of
the “palæontological” record. It affords hundreds of proofs of evolution,
but not a single proof of selection. Its “intermediate” and “connecting
links” do possibly prove the affiliation of species and the validity of
genealogical trees. But precisely the “intermediate links” which
_selection_ requires—the myriads of forms of life which were not
successfully adapted, the unfit competitors in the struggle for existence
which must have accompanied the favourably adapted variants from step to
step, from generation to generation—these are altogether awanting.
Another circumstance seems to us to have been entirely overlooked, and it
is one which gives the theory of selection an inevitable appearance of
truth, even if it is essentially false, and thus makes it very difficult
to refute. Assuming that the recognition of teleological factors is valid,
that there is an inward law of development, that “Moses” or whoever one
will was undoubtedly right, it is self-evident that, because of the
indubitable over-production of organisms, there would even then be a
struggle for existence on an immense scale, and that it would have a
far-reaching “selective” influence, because of the relative plasticity of
many forms of life. Beyond doubt it would, in the course of æons, have
applied its shears to many forms of life, and probably there would be no
organisms, organs, or associations in the evolution of the ultimate form
of which it had not energetically co-operated. Its influence would,
perhaps, be omnipresent, yet it might be far from being the all-sufficient
factor in evolution; indeed, as far as the actual impulse of evolution is
concerned, it might be a mere accessory. Unless we are to think of the
forms of life as wholly passive and wooden, the struggle for existence
must necessarily be operative, and the magnitude of its results, and their
striking and often bizarre outcome, will tend ever anew to conceal the
fact that the struggle is after all only an inevitable accompaniment of
evolution. And thus we understand how it is that interpretations from the
point of view of an inward law of development, of orthogenesis, or of
teleology, notwithstanding their inherent validity, have _à priori_ always
had a relatively difficult position as compared with the Darwinian view.
It is usual to speak of the “all-sufficiency of natural selection,” yet
the champion of the selection-theory admits, as he needs must, that the
struggle for existence and selection can of themselves create absolutely
nothing, no new character, no new or higher combination of the vital
elements; they can only take what is already given; they can only select
and eliminate among the wealth of what is offered.(38) And the offerer is
Life itself by virtue of its mysterious capacity for boundless and
inexhaustible variability, self-enrichment and increase. The “struggle for
existence” only digs the bed through which life’s stream flows, draws the
guiding-line, and continually stimulates it to some fresh revelation of
its wealth. But this wealth was there from the beginning; it was, to use
the old word, “potential” in the living, and included with it in the
universal being from which life was called forth. The struggle for
existence is only the steel which strikes the spark from the flint; is,
with its infinite forms and components, only the incredibly complex
channel through which life forces its way upwards. If we keep this clearly
in mind, the alarming and ominous element in the theory shrinks to half
its dimensions.
And, finally, if we can rid ourselves of the peculiar fascination which
this theory exercises, we soon begin to discover what extraordinary
improbability and fundamental artificiality it implies. “Utility” is
maintained to be that which absolutely, almost tyrannically, determines
form and development in the realm of the living. Is this an idea that
finds any analogy elsewhere in nature? Those who uphold the theory most
strongly are wont to compare the development of organisms to
crystal-formation in order in some way to tack on the living to the
not-living. Crystal-formation, with its processes of movement and
form-development, is, they say, a kind of connecting link between the
living and the not-living. And in truth we find here, as in the realm of
life, species-formation, development into individuals, stages and systems.
But all this takes place without any hint of “struggle for existence,” of
laboriously “selective” processes, or of ingenious accumulation of
“variations.” The “species” of crystals are formed not according to
utility, but according to inherent, determining laws of development, to
which the diversity of their individual appearances is due. If “Life” were
only a higher potential of what is already stirring in crystallisation, as
this view suggests, then we should expect to find fixed tendencies,
determined from within, in accordance with which life would pass through
the cycle of its forms and possibilities, and rise spontaneously through
gradual stages.